A dual-beam antenna (also called twin beam antenna) is known which radiates two beams in different directions using common plural antenna elements arranged in the horizontal direction (see, e.g., JP 5324014 B2 and WO 2010/059186 A2).
Power feed circuit for dual-beam antenna has two power feed terminals for inputting a power-feed signal and is configured that the power-feed signal input from the two input terminals is distributed to each antenna element, and the power and phase of the power-feed signal supplied to each antenna element are respectively adjusted, thereby adjusting the radiation directions, etc., of two beams.
JP 5324014 B2 and WO 2010/059186 A2 disclose the configurations of power feed circuit when three, four or six antenna elements are arranged horizontally.